This invention relates generally to the packaging of forms, and more particularly to the boxing of stacked forms, such as continuous form paper of the type used by computer printers.
Computer printout paper is conventionally printed from large rolls, divided lengthwise into a desired width, and perforated and accordion-folded at page intervals to form a stack of continuous forms. The following description proceeds with reference to forms of this type, but the invention is also applicable to packaging of other kinds of forms.
For ease of shipment and handling, it is desirable to package the forms in boxes. Conventionally, this task is performed manually, using a regular slotted container (RSC), which is a commonly available type of corrugated cardboard box having flaps on both top and bottom. This procedure typically requires at least two workmen for each form manufacturing and packaging line. Conventional form printing and cutting machinery outfeeds the form paper in several parallel continuous stacks onto a tray. There, one workman separates from each continuous stack discrete stacks of equal numbers of sheets, for example, 4,000 sheets per stack. The containers are conventionally provided in folded form, known as "knockdown" containers, which the second workman erects by manually opening them one at a time, upside down and folding and taping the bottom flaps thereof. Then, with the container still turned upside-down, it is fitted downwardly over a discrete stack of forms. The top flaps of the container assist in guiding the sides of the box downward along the edges of the stacked forms. Once filled, each container is turned over and closed by the workmen manually pressing down the stack of forms and folding and taping the top flaps down atop the forms.
Ideally, the containers are sized in their vertical dimension between the top and bottom flaps (i.e., height) such that the forms are level with the fold lines of the flaps. It is undesirable to underfill the boxes because the forms will shift and wrinkle during shipment. It is likewise undesirable to overfill the box because that makes it difficult to close the top flaps without bending them above their fold lines.
Unfortunately, this ideal is difficult to meet, consistently with providing an equal number of forms in each container in a large production run of forms. The caliper of the forms paper is not constant from roll to roll and therefore the height of stacks of forms of equal number of sheets can vary significantly. This circumstance makes it very difficult to provide a constant number of forms in a single size box and yet neither underfill not overfill the box. Workmen are unable manually to compress a tall stack of forms by a substantial amount if the container is overfilled. Therefore, various measures have been adopted in an effort to deal with this problem.
One approach is to use a regular-slotted container of sufficient height to accept a stack of forms of the thickest typical caliper and then to add corrugated cardboard shims in sufficient number to fill out any containers which are underfilled by paper of thinner caliper. However, this approach is wasteful, both in the cost of using larger size boxes and in the use of substantial quantities of corrugated cardboard as shims.
Another approach is systematically to provide more sheets in each stack of forms than is specified to the customers, for example, 4,100 sheets where 4,000 sheets is specified, and to use a regular-slotted container sized to accept the median height of the stacks of forms. Substantially fewer shims are required to fill out underfilled containers. If the container is overfilled, a portion of the stack of forms is torn off and discarded to enable closing the box. However, this approach is also wasteful and substantial care must also be taken to avoid shorting the customers on the number of sheets supplied in a stack. Moreover, regardless of which approach is taken to filling the boxes, substantial labor is required manually to package the forms.
Two attempts are known to have been made to automate the boxing of forms. One system proposed to provide an infeed conveyor for infeeding a stack of forms in an infeed direction to an elevator positioned beneath mechanism for erecting and supporting a regular slotted carbon. Knockdown cartons are infed from the opposite direction to the erecting apparatus. This design called for elevating the stack of forms and at the same time lowering the carton to insert the stacked forms into the open bottom of the carton. Thereupon, a bottom-folding mechanism comprising a pair of hinged plates folds the minor bottom flaps of the carton one at a time as the elevator, constructed in two vertically divided parts, was retracted downwardly one part at a time. Then, the major bottom flaps are closed. Next, with the bottom-closing mechanism still supporting the filled carton, the carton was to be pushed in the infeed forms direction onto an outfeed conveyor spaced above the forms infeed conveyor and below the carton infeed mechanism, for closing the top flaps. This design was subsequently abandoned without testing.
A second proposal provided apparatus for erecting a regular slotted container and positioning the container beneath an elevated form-dropping mechanism. Knockdown containers are infed to a container erecting mechanism spaced a distance laterally from the dropping mechanism, on opposite sides of a low wall. During erection, the knockdown containers were oriented on their sides with their top and bottom flaps extending laterally in opposite directions. One at a time, each container is opened and its bottom flaps closed and glued. Then, the container would be flipped over the low wall to right it on a box infeed conveyor, bottom flaps down, and positioned to align it beneath the dropping mechanism.
The form-dropping mechanism includes two pairs of parallel, end-to-end abutting fingers, in the form of powdered conveyor rollers. Each set of fingers is mounted on a normal frame member laterally movable to separate the fingers lengthwise to drop the forms. A pair of walls or fences is positioned above the fingers parallel to the frame members and movable laterally to center the stack in the dropping mechanism.
Stacks of forms are infed in the opposite direction from the direction containers are input via a conveyor to an elevator to be raised, one stack at a time, to the elevation of the dropping mechanism for dropping into the underlying box. The top flaps of the container are retained in an upwardly laterally extended position so as to funnel the dropped stack of forms downward into the box. After being filled, the box is conveyed normally of stack infeed conveyor out from beneath the dropping mechanism and to a case sealer. The case sealer included a pressing mechanism in the form of separate "feet" for compressing the forms in the box and then quickly retracting to allow closure of the top flaps. The top flaps were then glued and the box discharged. Meanwhile, the stack infeed elevator is lowered to the infeed conveyor to receive another stack of forms. The case erector proceeds to erect another regular slotted container and to flip the same over the wall to be positioned beneath the form-dropping mechanism.
Such a system was constructed and operated for a time, but was never able to be made to operate satisfactorily. Use of this system also suffered from all of the above-described drawbacks of manually packaging the forms in regular-slotted containers, particularly in the requirement of a capability to insert sufficient shims to fill out an underfilled box. For these reasons and because of its very substantial cost, this design was ultimately abandoned.
Accordingly, a need remains for an effective and economical system including apparatus and method for boxing printed forms.